Sliding discharge gate in conceptions have been known in their general principles for several decades, but in recent years they have progressively begun to substitute rod-type gates.
The principal advantages of sliding discharge gates with respect to rod-type gates consists essentially in the fact that the refractories which form the obturator last longer, as well as the fact that they can be exchanged from outside the ladle without waiting to cool the ladle to allow access of workmen to its interior. However, also in sliding discharge gates of known type there are some inconveniences:
First of all, it is not always easy to replace the refractory elements which must attend to the discharger sealing.
Secondly, said refractory material elements may break on account of the thermal variations which they undergo.
Thirdly, it is not easy to control the relative position of the sliding discharge gate during its operations.
Finally, it happens in known devices that the discharge gate opening and closing movement causes irregular wear to the various parts of refractory material elements, so that said elements must be replaced after comparatively short operation periods.